By the definition closest to your argument (that the Roman Republic's final chain of civil wars started with Gaius Marius-Gracchus was a populist, but I can't define his fall as a civil war), the Republic ruled Greece for fifty years and absorbed its culture quite thoroughly. (Not sure if that counts as "using the territory", though.) That's longer than the colonies of some latter day European empires (much of the German Empire, for example.) The Empire ruled it for longer, yes, but that's a good generation of people under Roman leadership before the SPQR starts to crumble.
But this argument is useless to the core of the thread. It is undeniable that Greeks varied. I just think that an invasion is likely to result in bad things being done to Athens (the destruction of a city-and, we can't forget, its citizen army), one of the "freer" Greek city states and the one which produced the greatest philosophers of the Greeks. At least, the ones we remember today. This will put a major dent in Greek philosophy.
So, guys, as the title of the thread is "What if the Persians conquered Greece?", rather than "Grudge match of Esopo vs. his critics", what sort of beliefs could emerge instead? I remember something buried in the arguments about there being less xenophobia and snobbery to do with other peoples, and a greater Greek unity.
(Which, personally, I disagree with. When after the Persian wars people wrote of the Greeks vs. the foreigners, they damn well knew who they were talking about in terms of an identity, if note a unified political system. The Persian wars helped define it. And no, I can't provide any examples. Sorry guys. It's a fact I "just know" from some book I've read.)